Oil-circuit breaker.



H. R. SCHULTZ.

0H. CIRCUIT BREAKER.

APPLlcATlou FILED MAR. 2o, 2912.

@tamed Jim. 30, 91?.

WITNESSES:

HJALMAR RUDMAN SCHULTZ, OF TRAFFORD PARK, MANCHESTER, ENGLAND, ASSIGNOR TO WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, A -CORPORA'IIION OF FENNSYLVANIA.

OIL-CIRCUIT BREAKER.

Specification of Lettersatent.

Patented Jan. 30, 191?.

To all whom t mgg/ concern:

Be it knoivndthat l, HJALMAR RUDMAN Ser-IUAV, a subject of the King of Sweden, and a resident of Trafford Park, Manches er` England, have invented a newY and useful lmproven'ient in Oil-Circuit Breakers, of which the following is a specification.

My invention relates to switches or interrupters for electric circuits and particula rl v to devices of this character which have their contact terminals immersed in oil or other insulating liquid.

The object ot the invention is to provide an improved construction which will prevent undue heating of interrupters that are designed for carrying large currents.

lt is Well known that a considerable rise ot temperature occurs in solid conductors of large cross-section carrying an alternating current of a certain value b y reason of what has been termed the skin effect et the conductor, although a direct current or" corresponding yamount can be carried by the same conductor without undue heating. "he skin effect increases with the size of the conductor, since the value of the ratio of area of cross-section to perimeter of the same increases with the increase of dimensions of the conductor. It 4is also Well known that any joint in a conductor unless particularly Well made, will occasion a local rise of temperature When a current is passing.

According to the present invention7 the above disadvantages are avoided in switches and circuit interrupters by constructing each pole of a plurality of parts insulated from each other and each having the ratio of the area to the perimeter of its crosssection small enough to render the skin effect negligible. Furthermore, the stationary contact terminals and the conductors leading thereto from the terminals of the rftch or interruptor -are made of single of metal without any joint, except 'lining pieces are riveted to the stacontact terminals for the purpose with will non' ced with reterence to the accompanying drawing in Winch- Figure 1 is front elevation of the stationary and movable Contact terminals of a dangerous heating.

switch or interrupter constructed in accordance with the invention. Fig. 2 is a side elevation ot' one of the stationary contact terminals, and Fig. 3 is a. similar view oi the movable contact member. l

The switch shown in the drawing is designed i'or a curient-carrying capacity of about `2000 amperes and each ot' the conductors forming the stationary contact terminals is constructed in three parts indicated at 1, 2 and 3. each or" which is adapted to carry amperes. it being found that with conductors of this size the skin eiiect is so small as to be negligible. The conductors are made of copper strap the thickness of which is about onetenth of the width and the ends are thickened by having side pieces 4 and 5 riveted thereto so as to provide a suiiciently large contact surface.

The joints between the strips and the thickening pieces do not carry the main current and, therefore, are not a source of In place of attaching side pieces to the conductors, the ends may be forged out or otherwise thickened if desired.

The ends of the conductors are bolted together by bolts 6, paper or other sheet insulation 7 being interposed between. The movable contact member is also composed of three parts 8, 9 and 10, each consisting of a straight brush supported in a holderl 11 that is pivoted by a pin 12 to a block 13. The block 13 is secured to the lower end o' an operating rod 14, and enough play is allowed for the brushes to Swing easily on the pivot to permit the same to take a fair bearing on the stationary Contact terminals. Each brush is preferably adjustable in its holder So as to insure that it shall make goed connection with the stationary contact terminals independently of the other brushes. The ends of the movable brushes are beveled and the stationary contact terminals are cut to a corresponding angie, in the usual manner.

ln the drawing, arcing tips 15 are shown as carried by a resilient bar 1G that is attached to the movable contact member, and corresponding stationary tips 1'? are secured le to the main stationary contact terminals by screws 18. ln order to support the static-irA ary contact terminals in their proper positions, the conductors l, 2 and 3 are held in clamps 13 that are bolted to the main trame l ier suitable distance pieces 2O and being inserted .where neces- (not shown), insulation 21 sary.

The switch shown in the drawings is of the kind that is adapted to have their contact members immersed in oil, but my invention is obviously applicable to circuit interrupters of all kinds, whether operated automatically or otherwise, and' its use is not limited to interrupters for alternating electric currents, although it is specially de- Signed for the purpose of avoiding the heating due to the skin eect as above mentioned. I claim as my invention: 1. A terminal member for circuit interrupters comprising a plurality of side-by- V side groups of superposed conductors having air ducts therebetween, a cradle for each of the Said groups' and a supporting' member, said cradles being. pivotally mounted on the supporting member.

2. A terminal member for circuit interrupters comprising a plurality'of side-byside groups of super-posed conductors, a holder for each of-the said groups and a Supporting member, said holders-being independently pivoted on the said supporting member.

sai-moes A terminal member for circuit interlupters comprising a plurality of side-byside groups of superposed conductors having air ducts therebetween, a holder t'or each of the said 'side-by-side groups and a supporting member, said holders being pivotally mounted on' the said supporting member.

4. A terminal member for circuit interr rupters comprising a plurality of side-byside groups of conductors, a supporting member and holders for each of the said groups, said holders being pivotally connected to the said supporting members.

5. l terminal member for circuit interrupters and similar devices comprising a plurality of side-by-side groups of superposed conductors, a pivotally'mounted support for each of said groups of conductors, and a member to which the said'supports are pivoted.

In testimony7 whereof, I have hereunto subscribed my nam'lf this 27th day of Feb `ruary, 1912.

Witnesses:

J. S. PECK, MILES WALKER.

HJALMAR RUDMAN SCHULTZ. 

